Like some humans, some monkeys drink more alcohol than others. Correlational studies suggest that various social factors, taste preferences, and physiological reactions to alcohol may account for the variability in consumption. Ethical and legal considerations preclude strict experimental investigation of such factors in man. This prospective study will determine, in monkeys, the extent to which the onset of alcohol consumption is related to five factors: group density, social tension, and dominance status of the individual in the living group, taste preferences and physiological responses to alcohol. Twelve groups of three monkeys each will be studied in a two-phase experiment. In the first phase the subjects will have a choice of orange juice or water; in the second, a choice of an alcohol-orange juice mixture or water. The consumption of each fluid by each individual will be monitored 24 hours a day. During each phase of the study, each group will be put through a set series of changes in social composition. Manipulation of group size will be used to determine the influence of social density on consumption. Group tension and individual status will be measured to determine whether they relate to the alcohol consumption of individual animals. Orange juice consumption in phase I will indicate taste preference. Major questions to be addressed are: Does social density influence individual consumption of alcohol? Is its influence interactive with the degree of social tension in the group and/or the social status of the individual? Do individual taste preferences or physiological reaction to alcohol influence consumption? Results of this study will improve our understanding of how personal characteristics and social conditions surrounding an individual's first exposures to alcoholic beverages influence alcohol consumption patterns that can lead to addiction and alcoholism.